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        1 2     

  Subjects -> VETERINARY SCIENCE (Total: 192 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brno     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 1)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 7)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 9)
American Journal of Primatology     Hybrid Journal   (Followers: 6)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 15)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 2)
Animal Behaviour     Hybrid Journal   (Followers: 325)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 4)
Animal Health Research Reviews     Hybrid Journal   (Followers: 4)
Animal Reproduction Science     Hybrid Journal   (Followers: 5)
Animals     Open Access   (Followers: 5)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Full-text available via subscription   (Followers: 7)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 4)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 2)
Australian Veterinary Journal     Hybrid Journal   (Followers: 10)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 4)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 3)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 1)
Bangladesh Veterinarian     Open Access   (Followers: 1)
BMC Veterinary Research     Open Access   (Followers: 5)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription  
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 6)
Case Reports in Veterinary Medicine     Open Access   (Followers: 4)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access  
Companion Animal     Full-text available via subscription   (Followers: 5)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 2)
Equine Health     Full-text available via subscription   (Followers: 1)
Equine Veterinary Education     Hybrid Journal   (Followers: 8)
Equine Veterinary Journal     Hybrid Journal   (Followers: 10)
Ethiopian Veterinary Journal     Open Access   (Followers: 4)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Frontiers in Veterinary Science     Open Access  
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 6)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 3)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
InVet     Open Access  
Iranian Journal of Applied Animal Science     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 2)
Journal of Veterinary Science & Technology     Open Access   (Followers: 3)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 4)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 10)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 2)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Small Animal Practice     Hybrid Journal   (Followers: 8)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 21)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (Followers: 2)
Journal of the Selva Andina Research Society     Open Access  
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 3)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 4)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 5)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 10)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 12)
Journal of Veterinary Medical Education     Partially Free   (Followers: 9)
Journal of Veterinary Medicine     Open Access   (Followers: 4)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 2)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 4)
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 1)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 1)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 3)
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)

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Journal Cover   Veterinary Microbiology
  [SJR: 1.425]   [H-I: 84]   [10 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
   Published by Elsevier Homepage  [2586 journals]
  • Identification and characterization of a novel antigenic epitope in the
           hemagglutinin of the escape mutants of H9N2 avian influenza viruses
    • Abstract: Publication date: Available online 23 April 2015
      Source:Veterinary Microbiology
      Author(s): Yinbiao Zhu , Da Yang , Qian Ren , Yang Yang , Xin Liu , Xiulong Xu , Wei Liu , Sujuan Chen , Daxin Peng , Xiufan Liu
      H9N2 avian influenza virus (AIV) evolves rapidly in both genovariation and antigenicity. It is essential to monitor the change of antigenicity, in particular in the hemagglutinin (HA) protein. Here we reported the selection of antigenic variants from A/Chicken/Shanghai/F/98 (H9N2) and A/chicken/Taixing/10/2010 (H9N2) viruses using HA-specific monoclonal antibodies (MAbs). Based on the reactivity of these variant and wild-type strains with the MAbs, we identified 6 critical amino acid positions (92, 145, 166, 167, 168, and 197) in the H9 antigenic sites, including the position 92 that has never been reported. Among AIVs originated from chicken in mainland China, the rates of Gly and Arg at position 92 within BJ/94-like (A/chicken/Beijing/1/1994) lineage viruses were 62.2% (28/45) and 37.8% (17/45), respectively; whereas the rates of Gly and Arg at position 92 within Y280-like (A/duck/Hong Kong/Y280/97) lineage viruses were 0.3% (2/670) and 99.1% (673/679), respectively. Our study suggests that G92R mutation together with other identified antigenic sites may serve as molecular markers for H9N2 virus evolution, and may aid improving AIV vaccine effectiveness


      PubDate: 2015-04-27T04:01:53Z
       
  • Generation of hepatitis E virus-like particles of two new genotypes G5 and
           G6 and comparison of antigenic properties with those of known genotypes
    • Abstract: Publication date: Available online 24 April 2015
      Source:Veterinary Microbiology
      Author(s): Tian-Cheng Li , Michiyo Kataoka , Kazuaki Takahashi , Sayaka Yoshizaki , Takanobu Kato , Koji Ishii , Naokazu Takeda , Shunji Mishiro , Takaji Wakita
      In addition to the four major genotypes (G1 through G4) known for human hepatitis E virus (HEV), two new genotypes (G5 and G6) were suggested, based on unique viral nucleotide sequences derived from wild boars in Japan. It has been unknown whether the virus of these new genotypes can cause hepatitis in humans; neither G5 nor G6 HEV has been found in patients to date. To study the antigenic properties of G5 and G6 HEV, we expressed N-terminus-truncated HEV ORF2 protein by a recombinant baculovirus system, and we obtained virus-like particles (VLPs) for both G5 and G6. The VLPs showed antigenic cross-reactivity against G1, G3 and G4 HEV more strongly than against ferret or rat HEV. Moreover, both anti-G5 and anti-G6 VLPs antibodies could neutralize G3 HEV's ability to infect PLC/PRF/5 cells, suggesting that G5 and G6 HEV have the same serotype as human HEV.


      PubDate: 2015-04-27T04:01:53Z
       
  • Recombination between Streptococcus suis ICESsu32457 and Streptococcus
           agalactiae ICESa2603 yields a hybrid ICE transferable to Streptococcus
           pyogenes
    • Abstract: Publication date: Available online 24 April 2015
      Source:Veterinary Microbiology
      Author(s): Emanuela Marini , Claudio Palmieri , Gloria Magi , Bruna Facinelli
      Integrative conjugative elements (ICEs) are mobile genetic elements that reside in the chromosome but retain the ability to undergo excision and to transfer by conjugation. Genes involved in drug resistance, virulence, or niche adaptation are often found among backbone genes as cargo DNA. We recently characterized in Streptococcus suis an ICE (ICESsu32457) carrying resistance genes [tet(O/W/32/O), tet(40), erm(B), aphA, and aadE] in the 15K unstable genetic element, which is flanked by two ∼1.3kb direct repeats. Remarkably, ∼1.3-kb sequences are conserved in ICESa2603 of S. agalactiae 2603V/R, which carry heavy metal resistance genes cadC/cadA and mer. In matings between S. suis 32457 (donor) and S. agalactiae 2603V/R (recipient), transconjugants were obtained. PCR experiments, PFGE, and sequence analysis of transconjugants demonstrated a tandem array between ICESsu32457 and ICESa2603. Matings between tandem array-containing S. agalactiae 2603V/R (donor) and S. pyogenes RF12 (recipient) yielded a single transconjugant containing a hybrid ICE, here named ICESa2603/ICESsu32457. The hybrid formed by recombination of the left ∼1.3-kb sequence of ICESsu32457 and the ∼1.3-kb sequence of ICESa2603. Interestingly, the hybrid ICE was transferable between S. pyogenes strains, thus demonstrating that it behaves as a conventional ICE. These findings suggest that both tandem arrays and hybrid ICEs may contribute to the evolution of antibiotic resistance in streptococci, creating novel mobile elements capable of disseminating new combinations of antibiotic resistance genes.


      PubDate: 2015-04-27T04:01:53Z
       
  • Cutaneous abscess caused by Corynebacterium lactis in a companion dog
    • Abstract: Publication date: Available online 24 April 2015
      Source:Veterinary Microbiology
      Author(s): João Marcelo Azevedo de Paula Antunes , Márcio Garcia Ribeiro , Larissa de Castro Demoner , Juliana Nunes Ramos , Paulo Victor Pereira Baio , Liliane Simpson-Louredo , Cíntia Silva Santos , Raphael Hirata Jr , Rachel Beneton Feriol , Adriana Resmond Cruz Romera , Verônica Viana Vieira , Ana Luíza Mattos-Guaraldi
      Many new, emerging and re-emerging diseases of humans are caused by pathogens which originate from animals or products of animal origin. Corynebacterium lactis, a recently described species of the genus Corynebacterium, was first isolated from milk of asymptomatic cows. In the present study a cutaneous abscess caused by C. lactis in a dog was recognized by cytologic and histologic examination in addition to 16S rRNA gene analysis of the microorganism. Therefore, C. lactis should be included among other bacterial species recognized as emerging pathogens for companion animals.


      PubDate: 2015-04-27T04:01:53Z
       
  • Outbreak of Salmonella enterica serovar Typhimurium phage type DT41 in
           Danish poultry production
    • Abstract: Publication date: Available online 25 April 2015
      Source:Veterinary Microbiology
      Author(s): Charlotta Löfström , Ann-Sofie Hintzmann , Gitte Sørensen , Dorte Lau Baggesen
      Salmonella enterica subspecies enterica serovar Typhimurium (S. Typhimurium) is one of the most prevalent serovars in Europe - where both poultry and poultry related products are common sources of human salmonellosis. Due to efficient control programs, the prevalence of S. Typhimurium in Danish poultry production is very low. Despite this, during the past decades there has been a reoccurring problem with infections with S. Typhimurium phage type DT41 in the Danish poultry production without identifying a clear source. In the end of 2013 and beginning of 2014 an increased isolation of S. Typhimurium DT41 was noted mainly in this production, but also in other samples. To investigate this is in more detail, 47 isolates from egg layers (n=5, 1 flock), broilers (n=33, 13 flocks), broiler breeding flocks and hatches (n=5; 2 flocks and 1 environmental hatchery sample), feed (n=1), poultry slaughter house (n=3, environmental sample and meat) were typed with multi locus variable number of tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE) to investigate the epidemiology of the outbreak. Based on PFGE results isolates were divided into four groups (Simpson's index of diversity (DI)=0.24±0.15). Due to the low DI, PFGE was not sufficient to provide information to unravel the outbreak. Based on MLVA typing the DT41 - (42/47 isolates) and the RDNC isolates (5/47) were split into nine groups (DI=0.65±0.14). When a maximum divergence at one locus was permitted these could be gathered into four groups. Using this criterion, combined with epidemiological information, a spread of one type from broiler breeders to broilers and further to the poultry slaughter house was plausible. In conclusion, although it could be concluded that a spread within the broiler production pyramid had taken place the source of the sudden increase of S. Typhimurium DT41 remains unclear. To investigate this in more detail, further studies using whole genome sequencing to obtain a higher discriminatory strength and including isolates from a longer period of time and from various sources are in progress.


      PubDate: 2015-04-27T04:01:53Z
       
  • Identification of three antigen epitopes on the nucleocapsid protein of
           the genotype C of bovine parainfluenza virus type 3
    • Abstract: Publication date: Available online 25 April 2015
      Source:Veterinary Microbiology
      Author(s): Jian-Le Ren , Yuan-Mao Zhu , Yue-Hui Zhou , Chuang Lv , Hao Yan , Lei Ma , Hong-Fei Shi , Fei Xue
      Bovine parainfluenza virus type 3 (BPIV3) is an important respiratory tract pathogen for both young and adult cattle. So far, three genotypes A, B and C of BPIV3 have been described on the basis of genetic and phylogenetic analysis. But fine mapping of epitopes of BPIV3 is scant and the antigenic variations among the three genotypes of BPIV3 have not been reported. Nucleocapsid protein (NP) is the most abundant protein in the virion and highly conserved in BPIV3, which is crucial for the induction of protective immunity in host. To identify antigenic determinants of BPIV3 NP, a panel of monoclonal antibodies (mAbs) was tested against a series of overlapping recombinant NP fragments expressed in E. coli. Firstly, six monoclonal antibodies (mAbs) against NP of the genotype C of BPIV3 (BPIV3c) were generated by using the purified BPIV3c strain SD0835 as immunogen and the recombinant NP of SD0835 as screening antigen. Then three antigen epitopes were identified with the six mAbs. One epitope 91GNNADVKYVIYM102 was recognized by mAb 5E5. The mAbs 7G5 7G8, 7G9, and 7H5 were reactive with another epitope 407FYKPTGG413. The third epitope 428ESRGDQDQ435 was reactive with mAb 6F8. Further analysis showed that the epitope (91-102 amino acids [aa]) was the most conserved and reactive with mAb 5E5 for all three genotypes of BPIV3 and HPIV3. The epitope (407-413 aa) was relatively conserved and reactive with mAbs 7G5, 7G8, 7G9, and 7H5 for BPIV3a, BPIV3c and HPIV3, but not reactive with BPIV3b. The epitope (428-435 aa) was less conserved and was reactive only with mAb 6F8 for BPIV3a and BPIV3c. These results suggested that there were evident antigenic variations among the three genotypes of BPIV3 and HPIV3. The mAb 6F8 could be used to detect BPIV3a and BPIV3c. The mAbs 7G5, 7G8, 7G9, and 7H5 might be used for differentiate BPIV3a, BPIV3c and HPIV3 from BPIV3b. The mAb 5E5 might be used for detecting all three types of BPIV3 and HPIV3. The results in this study would have potential applications in the development of suitable diagnostic techniques for BPIV3, which was prevalent in China.


      PubDate: 2015-04-27T04:01:53Z
       
  • A molecular epidemiology of treponemes in beef cattle digital dermatitis
           lesions and comparative analyses with sheep contagious ovine digital
           dermatitis and dairy cattle digital dermatitis lesions
    • Abstract: Publication date: Available online 21 April 2015
      Source:Veterinary Microbiology
      Author(s): L.E. Sullivan , N.J. Evans , R.W. Blowey , D.H. Grove-White , S.R. Clegg , J.S. Duncan , S.D. Carter
      Bovine digital dermatitis (BDD) is an infective foot disease commonly reported in dairy cattle where Treponema are considered as the primary causative infectious agents. There still remains little definitive information on the etiology of BDD in beef cattle suggesting further investigations are warranted. Beef BDD lesions (n =34) and healthy beef foot tissues (n =38) were analysed by PCR for three BDD-associated Treponema phylogroups and also for Dichelobacter nodosus and Fusobacterium necrophorum. Spirochete culture was attempted on all BDD lesion samples. One or more BDD-associated Treponema phylogroups were detected in 100% of beef BDD lesions. “Treponema medium/Treponema vincentii-like”, “Treponema phagedenis-like” and Treponema pedis spirochetes were identified in 27/34(79%), 31/34(91%) and 24/34(71%) of BDD lesions, respectively. No BDD-associated treponeme DNA was amplified from beef healthy foot tissues. D. nodosus and F. necrophorum were present in 24/34 (71%) and 15/34 (44%) of lesions and 10/38 (26%) and 12/38 (32%) of healthy foot tissues, respectively. Twenty spirochetes were isolated from beef BDD lesions; nineteen were representatives of the three BDD-associated Treponema phylogroups. One spirochete isolate shared less than 97% 16S rRNA gene similarity to the three cultivable BDD-associated Treponema phylogroups and therefore may represent a novel taxa of Treponema. Upon comparison, sheep contagious ovine digital dermatitis (CODD), dairy cattle and beef cattle BDD lesions appear to have extremely similar bacteriological data and therefore provides evidence of a shared etiopathogenesis posing concerns for cross-species transmission.


      PubDate: 2015-04-23T03:52:40Z
       
  • Mechanisms of antimicrobial resistant Salmonella enterica transmission
           associated with starling-livestock interactions
    • Abstract: Publication date: Available online 21 April 2015
      Source:Veterinary Microbiology
      Author(s): James C. Carlson , Doreene R. Hyatt , Jeremy W. Ellis , David R. Pipkin , Anna M. Mangan , Michael Russell , Denise S. Bolte , Richard M. Engeman , Thomas J. DeLiberto , George M. Linz
      Bird-livestock interactions have been implicated as potential sources for bacteria within concentrated animal feeding operations (CAFO). European starlings (Sturnus vulgaris) in particular are known to contaminate cattle feed and water with Salmonella enterica through their fecal waste. We propose that fecal waste is not the only mechanisms through which starlings introduce S. enterica to CAFO. The goal of this study was to assess if starlings can mechanically move S. enterica. We define mechanical movement as the transportation of media containing S. enterica, on the exterior of starlings within CAFO. We collected 100 starlings and obtained external wash and gastrointestinal tract (GI) samples. We also collected 100 samples from animal pens. Within each pen we collected one cattle fecal, feed, and water trough sample. Isolates from all S. enterica positive samples were subjected to antimicrobial susceptibility testing. All sample types, including 17% of external starling wash samples, contained S. enterica. All sample types had at least one antimicrobial resistant (AMR) isolate and starling GI samples harbored multidrug resistant S. enterica. The serotypes isolated from the starling external wash samples were all found in the farm environment and 11.8% (2/17) of isolates from positive starling external wash samples were resistant to at least one class of antibiotics. This study provides evidence of a potential mechanism of wildlife introduced microbial contamination in CAFO. Mechanical movement of microbiological hazards, by starlings, should be considered a potential source of bacteria that is of concern to veterinary, environmental and public health.


      PubDate: 2015-04-23T03:52:40Z
       
  • The role of the environment in transmission of Dichelobacter nodosus
           between ewes and their lambs
    • Abstract: Publication date: Available online 22 April 2015
      Source:Veterinary Microbiology
      Author(s): Mohd Muzafar , Leo A. Calvo-Bado , Laura E. Green , Edward M. Smith , Claire L. Russell , Rose Grogono-Thomas , Elizabeth M.H. Wellington
      Dichelobacter nodosus (D. nodosus) is the essential causative agent of footrot in sheep. The current study investigated when D. nodosus was detectable on newborn lambs and possible routes of transmission. Specific qPCR was used to detect and quantify the load of D. nodosus in foot swabs of lambs at birth and 5 -13hours post-partum, and their mothers 5-13hours post-partum; and in samples of bedding, pasture, soil and faeces. D. nodosus was not detected on the feet of newborn lambs swabbed at birth, but was detected 5-13h after birth, once they had stood on bedding containing naturally occurring D. nodosus. Multiple genotypes identified by cloning and sequencing a marker gene, pgrA, and by multi locus variable number tandem repeat analysis (MLVA) of community DNA from swabs on individual feet indicated a mixed population of D. nodosus was present on the feet of both ewes and lambs. There was high variation in pgrA tandem repeat number (between 3 and 21 repeats), and multiple MLVA types. The overall similarity index between the populations on ewes and lambs was 0.45, indicating moderate overlap. Mother offspring pairs shared some alleles but not all, suggesting lambs were infected from sources(s) other than just their mother's feet. We hypothesise that D. nodosus is transferred to the feet of lambs via bedding containing naturally occurring populations of D. nodosus, probably as a result of transfer from the feet of the group of housed ewes. The results support the hypothesis that the environment plays a key role in the transmission of D. nodosus between ewes and lambs.


      PubDate: 2015-04-23T03:52:40Z
       
  • Characterization of thymus atrophy in calves with subclinical BVD
           challenged with BHV-1
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): F. Romero-Palomo , M.A. Risalde , V. Molina , S. Lauzi , M.J. Bautista , J.C. Gómez-Villamandos
      Since the thymus is a target organ for the bovine viral diarrhea virus (BVDV), our experiment aimed to understand its relationship with the immunosuppressive effect by studying the consequences of a previous infection with BVDV on the thymus of calves challenged with bovine herpesvirus 1.1 (BHV-1). For this purpose, 12 animals were inoculated intranasally with non-cytopathic BVDV-1; 12 days later, 10 of them were coinfected intranasally with BHV-1. These animals were euthanized in batches of two at 0, 1, 2, 4, 7 or 14dpi with BHV-1. Another 10 calves were inoculated solely with BHV-1 and euthanized in batches of two at 1, 2, 4, 7 or 14dpi with BHV-1; two uninoculated calves were used as negative controls. Thymus samples from these animals were processed for viral detection and histopathological, immunohistochemical, and ultrastructural studies focused on BVDV/BHV-1 antigens, cortex:medulla ratio, apoptosis (TUNEL and caspase-3), collagen deposition, and factor VIII endothelial detection. Our study revealed the immunohistochemical presence of BVDV antigen in all animals in the BVDV-infected group, unlike BHV-1 detection, which was observed in animals in both infection groups only by molecular techniques. BVDV-preinfected animals showed severe atrophic changes associated with reduced cortex:medulla ratio, higher presence of cortical apoptosis, and increased collagen deposition and vascularization. However, calves solely infected with BHV-1 did not show atrophic changes. These findings could affect not only the numbers of circulating and local mature T cells but also the T cell-mediated immunity, which seems to be impaired during infections with this virus, thus favoring pathogenic effects during secondary infections.


      PubDate: 2015-04-09T15:23:53Z
       
  • Novel assay to quantify recombination in a calicivirus
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Sally J. Symes , Natalie Job , Nino Ficorilli , Carol A. Hartley , Glenn F. Browning , James R. Gilkerson
      Recombination is an important contributor to genomic evolution in many viral families, including the Caliciviridae. While it is known that genomic recombination in caliciviruses contributes to their rapid evolution, the precise molecular mechanisms are poorly understood. The majority of reported recombination events in feline calicivirus (FCV) occur at a “hot spot” between the non-structural protein coding region (open reading frame 1) and structural protein coding region (open reading frame 2). To gain a better understanding of the rate of recombination at this point, we developed a quantitative reverse transcription-polymerase chain reaction (RT-qPCR) assay to quantify the rate of recombination between two divergent strains of FCV during co-infection in cell culture. The assay utilised virus-specific primers upstream and downstream of the recombinational “hot spot” that hybridise with only one of the strains in the co-infection. Recombinant progeny that shared ORF1 sequence identity with one parental virus and ORF2 sequence identity with the other parental virus, and the site of recombination, was confirmed by sequencing the amplicon generated by the assay. Recombinants were detected in co-infected cells using this assay, but not in cells infected with single strains that were mixed together following infection, thus confirming its specificity. Recombination between two FCVs in co-infected cell cultures was estimated to occur at a rate of at least 6.8×10−6 single direction recombinant genomes per parental virus genome. Further application of this assay will enable factors influencing recombination in caliciviruses to be explored in greater detail, both in vitro and in vivo.


      PubDate: 2015-04-09T15:23:53Z
       
  • Adaptive amino acid substitutions enhance the virulence of an H7N7 avian
           influenza virus isolated from wild waterfowl in mice
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Qiang Chen , Zhijun Yu , Weiyang Sun , Xue Li , Hongliang Chai , Xiaolong Gao , Jiao Guo , Kun Zhang , Na Feng , Xuexing Zheng , Hualei Wang , Yongkun Zhao , Chuan Qin , Geng Huang , Songtao Yang , Jun Qian , Yuwei Gao , Xianzhu Xia , Tiecheng Wang , Yuping Hua
      Although H7N7 AIVs primarily circulate in wild waterfowl, documented cases of human infection with H7N7 viruses suggest they may pose a pandemic threat. Here, we generated mouse-adapted variants of a wild waterfowl-origin H7N7 virus to identify adaptive changes that confer enhanced virulence in mammals. The mouse lethal doses (MLD50) of the adapted variants were reduced >5000-fold compared to the parental virus. Mouse-adapted variants viruses displayed enhanced replication in vitro and in vivo, and acquired the ability to replicate in extrapulmonary tissues. These observations suggest that enhanced growth characteristics and modified cell tropism may increase the virulence of H7N7 AIVs in mice. Genomic analysis of the adapted variant viruses revealed amino acid changes in the PB2 (E627K), PB1 (R118I), PA (L550M), HA (G214R), and NA (S372N) proteins. Our results suggest that these amino acid substitutions collaboratively enhance the ability of H7N7 virus to replicate and cause severe disease in mammals.


      PubDate: 2015-04-09T15:23:53Z
       
  • IFC - Aims & Scope, EDB, Publication Information
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2




      PubDate: 2015-04-09T15:23:53Z
       
  • Synovial fluid cytology in experimental acute canine monocytic
           ehrlichiosis (Ehrlichia canis)
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Konstantina Theodorou , Leonidas Leontides , Victoria I. Siarkou , Theodoros Petanides , Konstantinos Tsafas , Shimon Harrus , Mathios E. Mylonakis
      Evidence-based information of a cause-and-effect relationship between Ehrlichia canis infection and polyarthritis in naturally- or experimentally-infected dogs is currently lacking. The aim of this prospective study was to investigate whether synovial fluid cytological evidence of arthritis could be documented in dogs with acute monocytic ehrlichiosis. Direct synovial fluid cytology smears from eight Beagle dogs experimentally infected with E. canis were examined prior to, and on 21, 35 and 63 days post-inoculation. The cytological variables assessed included cellularity, percentages of mononuclear cells and neutrophils, macrophage reactivity and evidence of E. canis morulae. The median cellularity and percentages of mononuclear cells and neutrophils prior to inoculation did not differ when compared to post-inoculation cytological evaluation. Increased cellularity, E. canis morulae or cytological evidence of arthritis or macrophage reactivity were not observed throughout the course of the study. In the present study, no cytological evidence of arthritis was found in dogs with experimental acute canine monocytic ehrlichiosis, suggesting that E. canis infection should be considered a rather uncommon cause of arthritis in dogs.


      PubDate: 2015-04-09T15:23:53Z
       
  • Prevalence of the immune evasion gene cluster in Staphylococcus aureus
           CC398
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Christiane Cuny , Mohamed Abdelbary , Franziska Layer , Guido Werner , Wolfgang Witte
      The immune evasion gene cluster (IEC) is typical for Staphylococcus aureus isolated from humans but is usually absent in S. aureus isolated from animals. Previous studies have shown that methicillin resistant S. aureus (MRSA) CC398 obviously lost the IEC when evolving as livestock-associated MRSA from a human-adapted, methicillin-susceptible ancestor. This study aimed to look for the presence of IEC in MRSA from pigs and horses as well as from the colonization of humans with occupational animal contact and from infections in humans. For comparison, methicillin susceptible S. aureus (MSSA) isolates from infections in humans were included. We did not detect the IEC among 94 isolates from the nasal colonization of pigs; however, the IEC was found in 6 of 61 isolates from nosocomial infections in horses. MRSA CC398 isolates from the nasal colonization of 138 pig farmers were negative for the IEC. It was detected, however, in 4 of 69 veterinarians treating horses. Among 99 epidemiologically unrelated MRSA isolates attributed to CC398 originating from infections in humans, 19 were positive for the IEC. Only three of these isolates which also contained luk-PV were attributed to the ancestral, human-adapted subpopulation of CC398 by means of PCR for detection of canonical SNPs. A considerable proportion of LA-MRSA CC398 attributed to the animal subpopulation and originating from infections in humans had acquired the IEC; this acquisition is, however, obviously not a prerequisite to the capacity of LA-MRSA CC398 to cause infections in this host. Among 15 MSSA CC398 isolates from infections in humans, 11 contained the IEC, and of these, two were attributed to the animal subpopulation. Six isolates containing both the IEC and luk-PV were attributed to the ancestral, human subpopulation. Re-acquisition of the IEC by LA-MRSA CC398 suggests readaptation to the human host. In epidemiological surveillance, discrimination from the ancestral human subpopulation is important.


      PubDate: 2015-04-09T15:23:53Z
       
  • Protective immunity against nervous necrosis virus in convict grouper
           Epinephelus septemfasciatus following vaccination with virus-like
           particles produced in yeast Saccharomyces cerevisiae
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Ga Ram Wi , Jee Youn Hwang , Mun-Gyeong Kwon , Hyoung Jin Kim , Hyun Ah Kang , Hong-Jin Kim
      Infection with nervous necrosis virus (NNV) causes viral nervous necrosis, which inflicts serious economic losses in marine fish cultivation. Virus-like particles (VLPs) are protein complexes consisting of recombinant virus capsid proteins, whose shapes are similar to native virions. VLPs are considered a novel vaccine platform because they are not infectious and have the ability to induce neutralizing antibodies efficiently. However, there have been few studies of protective immune responses employing virus challenge following immunization with NNV VLPs, and this is important for evaluating the utility of the vaccine. In the present study, we produced red-spotted grouper (Epinephelus akaara) NNV (RGNNV) VLPs in Saccharomyces cerevisiae and investigated protective immune responses in convict grouper (Epinephelus septemfasciatus) following intraperitoneal injection and oral immunization with the RGNNV VLPs. The parenterally administered VLPs elicited neutralizing antibody with high efficacy, and provided the fish with full protection against RGNNV challenge: 100% of the immunized fish survived compared with only 37% of the control fish receiving phosphate-buffered saline. RGNNV VLPs administered orally provoked neutralizing antibody systemically and conferred protective immunity against virus challenge: however only 57% of the fish survived. Our results demonstrate that RGNNV VLP produced in yeast has great potential as vaccine in fish.


      PubDate: 2015-04-09T15:23:53Z
       
  • Influenza A(H1N1)pdm09 virus in pigs, Togo, 2013
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Mariette F. Ducatez , Félix Awoume , Richard J. Webby
      We collected 325 nasal swabs from freshly slaughtered previously healthy pigs from October 2012 through January 2014 in a slaughterhouse near Lomé in Togo. Influenza A virus genome was detected by RT-PCR in 2.5–12.3% of the pooled samples, and results of hemagglutinin subtyping RT-PCR assays showed the virus in all the positive pools to be A(H1N1)pdm09. Virus was isolated on MDCK cells from a representative specimen, A/swine/Togo/ONA32/2013(H1N1). The isolate was fully sequenced and harbored eight genes similar to A(H1N1)pdm09 virus genes circulating in humans in 2012–2013, suggesting human-to-swine transmission of the pathogen.


      PubDate: 2015-04-09T15:23:53Z
       
  • Complete genome sequence of canine astrovirus with molecular and
           epidemiological characterisation of UK strains
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Sarah L. Caddy , Ian Goodfellow
      Astroviruses are a common cause of gastroenteritis in children worldwide. These viruses can also cause infection in a range of domestic and wild animal species. Canine astrovirus (CaAstV) was first identified in the USA, and has since been reported in dogs from Europe, the Far East and South America. We sought to determine whether CaAstV is circulating in the UK dog population, and to characterise any identified strains. Stool samples were collected from pet dogs in the UK with and without gastroenteritis, and samples were screened for CaAstV by qPCR. Four CaAstV positive samples were identified from dogs with gastroenteritis (4/67, 6.0%), whereas no samples from healthy dogs were positive (p <0.001). Sequencing of the capsid sequences from the four CaAstV strains found significant genetic heterogeneity, with only 80% amino acid identity between strains. The full genome sequence of two UK CaAstV strains was then determined, confirming that CaAstV conforms to the classic genome organisation of other astroviruses with ORF1a and ORF1b separated by a frameshift and ORF2 encoding the capsid protein. This is the first report describing the circulation of CaAstV in UK dogs with clinical signs of gastroenteritis, and the first description of the full-length genomes of two CaAstV strains.


      PubDate: 2015-04-09T15:23:53Z
       
  • The M949_1556 gene plays a role on the bacterial antigenicity and
           pathogenicity of Riemerella anatipestifer
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Jiechi Zou , Xiaolan Wang , Mingxing Tian , Shoulin Cao , Wanwan Hou , Shaohui Wang , Xiangan Han , Chan Ding , Shengqing Yu
      Riemerella anatipestifer is one of the most economically important pathogens of farm ducks worldwide. However, the molecular mechanisms regarding its antigenicity and pathogenicity are poorly understood. We previously constructed a library of random Tn4351 transposon mutants using R. anatipestifer strain CH3. In this study, M949_1556 gene inactivated mutant strain CH3ΔM949_1556 was identified by screening of the library using monoclonal antibody against R. anatipestifer serotype 1 lipopolysaccharide (LPS) (anti-LPS MAb) followed by sequence analysis. The mutant strain presented no reactivity to the anti-LPS MAb in an indirect ELISA. Animal studies showed that the median lethal dose (LD50) of CH3ΔM949_1556 was >1010 colony forming units (CFU), which was attenuated more than 50 times, compared with that of wild-type strain CH3 (LD50 =2×108 CFU). The bacterial loads in the blood of CH3ΔM949_1556 infected ducks were significantly decreased, compared with those of CH3-infected ducks. In addition, CH3ΔM949_1556 presented significant, higher susceptibility to complement-dependent killing than CH3 did in vitro. Furthermore, CH3ΔM949_1556 showed increased bacterial adhesion and invasion capacities to Vero cells. Immunization with CH3ΔM949_1556-inactived vaccine was effective in protecting the ducks from challenge with R. anatipestifer serotype 1 strain WJ4, serotype 2 strain Yb2 and serotype 10 strain HXb2, suggesting that the mutant strain CH3ΔM949_1556 could provide a broad cross-protection among R. anatipestifer serotypes 1, 2 and 10 strains. Our results demonstrated that the M949_1556 gene plays a role on the bacterial antigenicity and pathogenicity of R. anatipestifer.


      PubDate: 2015-04-09T15:23:53Z
       
  • Actinobacillus pleuropneumoniae two-component system QseB/QseC regulates
           the transcription of PilM, an important determinant of bacterial adherence
           and virulence
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Jinlin Liu , Linlin Hu , Zhuofei Xu , Chen Tan , Fangyan Yuan , Shulin Fu , Hui Cheng , Huanchun Chen , Weicheng Bei
      QseB/QseC is one of the five predicted two-component systems (TCSs) in Actinobacillus pleuropneumoniae. To understand the roles of this TCS in A. pleuropneumoniae, a markerless gene-deletion mutant ΔqseBC was constructed. Differentially expressed (DE) genes in ΔqseBC were filtered by microarray analysis. A total of 44 DE genes were found to be regulated by QseB/QseC system. The transcriptional profile of A. pleuropneumoniae ΔqseBC was compared with that of ΔluxS and catecholamine (CA) stimulations, 13 genes regulated by QseB/QseC were found also regulated by LuxS, and 3 Qse-regulons were co-regulated by CA stimulations, respectively. Binding of QseB to the promoters of three regulons (pilM, glpK and hugZ), which were co-regulated by QseB/QseC and LuxS, was evaluated by electrophoretic mobility-shift assay. Results indicated that pilM was directly regulated by phosphorylated-QseB. Then the pilM deletion mutant ΔpilM was constructed and characterized. Data presented here revealed that adherence ability of ΔpilM to St. Jude porcine lung cells was significantly decreased, and ΔpilM exhibited reduced virulence in pigs, suggesting PilM contributes to the process of A. pleuropneumoniae infection.


      PubDate: 2015-04-09T15:23:53Z
       
  • The Adh adhesin domain is required for trimeric autotransporter
           Apa1-mediated Actinobacillus pleuropneumoniae adhesion, autoaggregation,
           biofilm formation and pathogenicity
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Lei Wang , Wanhai Qin , Shuxin Yang , Ruidong Zhai , Liang Zhou , Changjiang Sun , Fengguang Pan , Qun Ji , Yu Wang , Jingmin Gu , Xin Feng , Chongtao Du , Wenyu Han , P.R. Langford , Liancheng Lei
      Actinobacillus pleuropneumoniae is a causative agent of porcine pleuropneumonia, which is a highly contagious endemic disease of pigs. Adhesion is a critical first step in the infection process. Trimeric autotransporter adhesions (TAAs) have been identified as novel virulence factors; however, little is known on their roles in A. pleuropneumoniae pathogenicity. Here, our data show that YadA-like head region (Adh) of Apa1 was the optimal adhesion functional domain via segment expression and adhesion assays in vitro. Additionally, Adh induced partial protection against A. pleuropneumoniae 5b L20 and serotypes 1, 3, and 5a in mice. The deletion of Adh gene significantly decreased autoaggregation, biofilm formation and adherence to host cells in vitro. Furthermore, with delaying of clinical symptoms, reducing production of pro-inflammatory cytokines and lessening the lung injury after infection, Adh deletion strain (5bϕAdh) significantly reduced the pathogenicity to piglets. To elucidate the mechanism of lung injury, the differentially expressed genes in the lung tissues of piglets infected with the 5b L20 or 5bϕAdh strains were investigated using microarray analysis and validated by qRT-PCR. Compared with the 5b L20 infected piglets, 495 genes were differentially expressed in 5bϕAdh infected lung tissue (221 upregulated and 274 downregulated). Especially, the antigen processing and presentation gene IFI30 was increased following infection with the 5bϕAdh strain. Thus, Adh may enhance pathogenicity by depressing host immune recognition. We conclude that the head domain of the A. pleuropneumoniae trimeric autotransporter Apa1 regulates autoagglutination, biofilm formation, adhesion to host cells and pathogenicity.


      PubDate: 2015-04-09T15:23:53Z
       
  • Detection of vancomycin-resistant Enterococcus faecalis ST6-vanB2 and E.
           faecium ST915-vanA in faecal samples of wild Rattus rattus in Spain
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Carmen Lozano , David González-Barrio , Jesús T. García , Sara Ceballos , Pedro P. Olea , Francisco Ruiz-Fons , Carmen Torres
      The detection of vancomycin-resistant-enterococci (VRE) among wild animals represents a worrisome public health concern. The objectives of the study were to determine the possible presence of VRE in faecal samples of wild small mammals in Spain, to characterize the vancomycin resistance mechanisms and genetic lineages of recovered isolates and to know the diversity of enterococcal species in these animals. A total of 155 faecal samples from small mammals were inoculated in Slanetz–Bartley agar supplemented or not with vancomycin (Van-SB/SB plates). The antimicrobial susceptibility profile to 12 antimicrobials and the presence of 20 antimicrobial resistance genes was analyzed. The structure of Tn1546 and the presence of gelE, cylA, asa, esp and hyl genes was studied. Multilocus-sequence-typing (MLST) technique was also performed. VRE isolates were recovered in Van-SB plates in 11 samples. Two samples contained vanB2-positive E. faecalis isolates of lineage ST6, which showed a multiresistance phenotype and harboured the virulence genes gelE and asa. One sample contained a vancomycin-resistant E. faecium isolate of the new lineage ST915, with the vanA gene included into Tn1546 (truncated with IS1542 and IS1216 elements). The vanB2 and vanA isolates were obtained from Rattus rattus. The remaining eight VRE-positive samples contained species with intrinsic vancomycin-resistance mechanisms: E. casseliflavus (n =5) and E. gallinarum (n =3). One hundred and forty-seven vancomycin-susceptible-enterococcal isolates were obtained in SB plates, and E. faecalis and E. faecium were the most frequent detected species. This is the first report of vanB2-containing enterococci in wild animals.


      PubDate: 2015-04-09T15:23:53Z
       
  • Presence and new genetic environment of
           pleuromutilin–lincosamide–streptogramin A resistance gene
           lsa(E) in Erysipelothrix rhusiopathiae of swine origin
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Anyun Zhang , Changwen Xu , Hongning Wang , Changwei Lei , Bihui Liu , Zhongbin Guan , Chunmei Yang , Yongqiang Yang , Linyao Peng
      Erysipelothrix rhusiopathiae is a Gram-positive bacillus that causes erysipelas in swine. In recent years, erysipelas infection among swine in China has been increasing. A combined resistance phenotype to pleuromutilins, lincosamides, and streptogramin A (PLSA phenotype) was found in some E. rhusiopathiae isolates. The aim of this study was to identify the resistance genes responsible for the PLSA phenotype in E. rhusiopathiae strains and to map the genetic environment of the identified resistance gene. A total of 46 E. rhusiopathiae isolates from 31 pig farms in China were studied. Minimum inhibitory concentrations (MICs) of 11 antimicrobial agents were determined by broth microdilution method. Seven were highly resistant to tiamulin (MICs 32μg/ml) and clindamycin (MICs 64μg/ml). Resistance genes responsible for the PLSA phenotype were screened by PCR. The lsa(E), spw, lnu(B), aadE and aphA3 genes were detected in strains had the PLSA phenotype, whereas none was detected in susceptible strains. The genetic environment of lsa(E) gene was determined by whole-genome sequencing and overlapping PCR assays. A novel multiresistance gene cluster, orf1-aadE-apt-spw-lsa(E)-lnu(B)-rec-orf2-orf1-aadE-sat4-aphA3, was found. Horizontal gene transfer experiments and whole-genome sequencing suggested that the lsa(E)-carrying multiresistance gene cluster was located in the chromosome. This is the first molecular characterization of PLSA resistance in E. rhusiopathiae. The lsa(E), spw and lnu(B) genes were found in E. rhusiopathiae for the first time. A novel lsa(E)-carrying multiresistance gene cluster was found. The location of lsa(E) in different gene cluster facilitates its persistence and dissemination.


      PubDate: 2015-04-09T15:23:53Z
       
  • Seroprevalence of Coxiella burnetii in domesticated and feral cats in
           eastern Australia
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Amanda J. Shapiro , Katrina L. Bosward , Jane Heller , Jacqueline M. Norris
      The seroprevalence of Coxiella burnetii (C. burnetii) in cats in eastern Australia is unknown, and the risk of transmission from cats to humans is undetermined. This study aimed to determine the exposure of cats to C. burnetii in four distinct cat subpopulations. An indirect immunofluoresence assay (IFA) and an Enzyme-linked immunosorbent assay (ELISA) used for detection of anti-C. burnetii antibodies in humans were adapted, verified for use on feline serum, and compared. Cat serum samples (n =712) were tested with IFA from four subpopulations [cattery-confined breeding cats, pet cats, feral cats and shelter cats]. The proportions of seropositive cats were; cattery-confined breeding cats (35/376, 9.3%), pets (2/198, 1%), feral cats (0/50), shelter cats (0/88). The significant variables in C. burnetii seropositivity were cattery-confined breeding cat subpopulation and sterilisation status, with infected cats 17.1 (CI 4.2–70.2; P <0.001) times more likely to be cattery-confined breeding cats and 6.00 (CI 2.13–16.89; P <0.001) times more likely to be entire than sterilised. ELISA was used on 143 of 712 sera tested with IFA, and the Cohen's Kappa coefficient of 0.75 indicated 92.2% agreement between the two assays. These results confirm that Australian cats have been exposed to C. burnetii and that a higher seroprevalence of C. burnetii is seen amongst cattery-confined breeding cats. Cat breeders and veterinary personnel involved in feline reproductive procedures may be at higher risk of exposure to C. burnetii.


      PubDate: 2015-04-09T15:23:53Z
       
  • Characterization of mucosa-associated bacterial communities in abomasal
           ulcers by pyrosequencing
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Alexandra Hund , Monika Dzieciol , Stephan Schmitz-Esser , Thomas Wittek
      Abomasal ulcers are important pathological alterations of the gastrointestinal tract in cattle and are exceptionally hard to diagnose in vivo. The microbiome of the abomasum in cattle with or without ulcers has hardly been studied to date, and if so, the studies used culture-dependent methods. In the present study, the bacterial communities associated with abomasal ulcers of slaughter cows, bulls, and calves in Austria were described using 16S rRNA gene pyrosequencing. Sequences were clustered into 10,459 operational taxonomic units (OTUs), affiliating to 28 phyla with Proteobacteria, Firmicutes, Bacteroidetes and Tenericutes dominating (96.4% of all reads). The most abundant genera belonged to Helicobacter, Acetobacter, Lactobacillus, and novel Mycoplasma-like phylotypes. Significant differences between the microbial communities of healthy and ulcerated calves compared to cows and bulls could be observed. However, only few statistically significant differences in the abundances of certain OTUs between healthy and ulcerated abomasal mucosa were found. Additionally, near full-length 16S rRNA gene sequences of the most abundant phylotypes were obtained by cloning and Sanger sequencing (n =88). In conclusion, our results allow the first deep insights into the composition of abomasal mucosal bacterial communities in cattle and describe a hitherto unknown high diversity and species richness of abomasal bacteria in cattle. Our results suggest that bacteria may have only limited involvement in the etiology of abomasal ulcers. However, future research will be needed to verify the contribution of bacteria to abomasal ulcer formation as presence or absence of bacteria does not necessarily correlate with etiology of disease.


      PubDate: 2015-04-09T15:23:53Z
       
  • Nasal immunization with M cell-targeting ligand-conjugated ApxIIA toxin
           fragment induces protective immunity against Actinobacillus
           pleuropneumoniae infection in a murine model
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Jisang Park , Ki-Weon Seo , Sae-Hae Kim , Ha-Yan Lee , Bumseok Kim , Chae Woong Lim , Jin-Hee Kim , Han Sang Yoo , Yong-Suk Jang
      Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia and severe economic loss in the swine industry has been caused by the infection. Therefore, the development of an effective vaccine against the bacteria is necessary. ApxII toxin, among several virulence factors expressed by the bacteria, is considered to be a promising vaccine candidate because ApxII toxin not only accompanies cytotoxic and hemolytic activities, but is also expressed in all 15 serotypes of bacteria except serotypes 10 and 14. In this study, we identified the peptide ligand capable of targeting the ligand-conjugated ApxIIA #5 fragment antigen to nasopharynx-associated lymphoid tissue. It was found that nasal immunization with ligand-conjugated ApxIIA #5 induced efficient mucosal and systemic immune responses measured at the levels of antigen-specific antibodies, cytokine-secreting cells after antigen exposure, and antigen-specific lymphocyte proliferation. More importantly, the nasal immunization induced protective immunity against nasal challenge infection of the bacteria, which was confirmed by histopathological studies and bacterial clearance after challenge infection. Collectively, we confirmed that the ligand capable of targeting the ligand-conjugated antigen to nasopharynx-associated lymphoid tissue can be used as an effective nasal vaccine adjuvant to induce protective immunity against A. pleuropneumoniae infection.


      PubDate: 2015-04-09T15:23:53Z
       
  • Three-year duration of immunity for feline herpesvirus and calicivirus
           evaluated in a controlled vaccination-challenge laboratory trial
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Dominique Jas , Valérie Frances-Duvert , Delphine Vernes , Pierre-Michel Guigal , Hervé Poulet
      Feline vaccination guidelines recommend less frequent boosters for the core vaccines (rhinotracheitis, calicivirosis and infectious panleucopenia). Most guidelines recommend boosters at 3-yearly intervals after a basic vaccination including primary vaccination and revaccination one year later. The objective of this study was to assess the duration of immunity induced by PUREVAX® RCPCh FeLV, a non-adjuvanted vaccine against feline rhinotracheitis, calicivirosis, infectious panleucopenia, chlamydiosis and leukemia. After primary vaccination followed by revaccination one year later with a vaccine formulated at minimum dose, the cats were kept in a confined environment and challenged 3 years later with a virulent heterologous strain of feline calicivirus (FCV) and subsequently a virulent strain of feline herpesvirus (FHV). Clinical signs and viral excretion were recorded for two weeks after each viral inoculation. Contemporary unvaccinated cats and new animals added at the time of challenge were used as controls. The vaccination regimen induced a stable and long-lasting humoral response. Vaccination resulted in a significant reduction in the severity of the disease after FHV challenge and in the frequency of cats showing a severe calicivirosis (defined as a combination of systemic clinical symptoms and oronasal ulcers). As opposed to the significant reduction of excretion observed a few weeks after primo-vaccination or even one year after vaccination for FCV, viral shedding was not reduced 3 years after revaccination. This study showed that primary vaccination and revaccination one year later with PUREVAX® RCPCh FeLV was able to induce 3-year duration of immunity against FCV and FHV. The results and conclusion of this study are consistent with current vaccination guidelines and will allow the veterinarian to adapt the vaccination regimen to the way of life of the cat.


      PubDate: 2015-04-09T15:23:53Z
       
  • Determination of common genetic variants within the non-structural
           
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): P. Nsamba , T.A.P. de Beer , M. Chitray , K. Scott , W. Vosloo , F.F. Maree
      The non-structural proteins of foot-and-mouth disease virus (FMDV) are responsible for RNA replication, proteolytic processing of the viral polyprotein precursor, folding and assembly of the structural proteins and modification of the cellular translation apparatus. Investigation of the amino acid heterogeneity of the non-structural proteins of seventy-nine FMDV isolates of SAT1, SAT2, SAT3, A and O serotypes revealed between 29 and 62% amino acid variability. The Leader protease (Lpro) and 3A proteins were the most variable whilst the RNA-dependent RNA polymerase (3Dpol) the most conserved. Phylogeny based on the non-structural protein-coding regions showed separate clusters for southern African viruses for both the Lpro and 3C protease (3Cpro) and sequences unique to this group of viruses, e.g. in the 2C and 3Cpro proteins. These groupings were unlike serotype groupings based on structural protein-coding regions. The amino acid substitutions and the nature of the naturally occurring substitutions provide insight into the functional domains and regions of the non-structural proteins that are critical for structure–function. The Lpro of southern African SAT type isolates differed from A, O and SAT isolates in northern Africa, particularly in the auto-processing region. Three-dimensional structures of the 3C protease (3Cpro) and 3Dpol showed that the observed variation does not affect the enzymatic active sites or substrate binding sites. Variation in the 3Cpro cleavage sites demonstrates broad substrate specificity.


      PubDate: 2015-04-09T15:23:53Z
       
  • Cross-protection of a new type 2 porcine reproductive and respiratory
           syndrome virus (PRRSV) modified live vaccine (Fostera PRRS) against
           heterologous type 1 PRRSV challenge in growing pigs
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Changhoon Park , Kyuhyung Choi , Jiwoon Jeong , Chanhee Chae
      The objective of the present study was to determine the cross-protection of a new type 2 porcine reproductive and respiratory syndrome virus (PRRSV) modified live vaccine against heterologous type 1 PRRSV challenge in growing pigs. The mean rectal temperature and respiratory score was significantly (P <0.05) lower in vaccinated challenged pigs than in unvaccinated challenged pigs. Vaccination of pigs with type 2 PRRSV reduced the levels of type 1 PRRSV viremia after challenge with type 1 PRRSV. Vaccinated challenged pigs had significantly (P <0.05) higher frequency of interferon-γ secreting cells and lower levels of interleukin-10 compared to unvaccinated challenged pigs. Vaccination of pigs with the type 2 PRRSV effectively reduced the macroscopic and microscopic lung lesion and the type 1 PRRSV antigens within lung lesions in vaccinated challenged pigs. This study demonstrates partial cross-protection of a new type 2 PRRSV modified live vaccine against heterologous type 1 PRRSV challenge in growing pigs.


      PubDate: 2015-04-09T15:23:53Z
       
  • Comparative analysis of cellular immune responses and cytokine levels in
           sheep experimentally infected with bluetongue virus serotype 1 and 8
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): P.J. Sánchez-Cordón , A.C. Pérez de Diego , J.C. Gómez-Villamandos , J.M. Sánchez-Vizcaíno , F.J. Pleguezuelos , B. Garfia , P. del Carmen , M. Pedrera
      Protective immunity in sheep with bluetongue virus (BTV) infection as well as the role of BTV-induced cytokines during immune response remains unclear. Understanding the basis immunological mechanisms in sheep experimentally infected with serotypes 1 and 8 (BTV-1 and -8) was the aim of this study. A time-course study was carried out in order to evaluate cell-mediated immune response and serum concentrations of cytokines (IL-1β, TNFα, IL-12, IFNγ, IL-4 and IL-10) with inflammatory and immunological functions. Depletion of T cell subsets (mainly CD4+, γδ and CD25+) together with the absence of cytokines (IFNγ and IL-12) involved in the regulation of cell-mediated antiviral immunity at the first stage of the disease suggested that both BTV-1 and BTV-8 might impair host's capability against primary infections which would favor viral replication and spreading. However, cellular immune response and cytokines elicited an immune response in sheep that efficiently reduced viremia in the final stage of the experiment. Recovery of T cell subsets (CD4+ and CD25+) together with a significant increase of CD8+ T lymphocytes in both infected groups were observed in parallel with the decrease of viremia. Additionally, the recovery of CD4+ T lymphocytes together with the significant increase of IL-4 serum levels at the final stage of the experiment might contribute to humoral immune response activation and neutralizing antibodies production against BTV previously described in the course of this experiment. These results suggested that both cellular and humoral immune response may contribute to protective immunity against BTV-1 and BTV-8 in sheep. The possible role played by IL-10 and CD25+ cells in controlling inflammatory and immune response in the final stage of the experiment has also been suggested.


      PubDate: 2015-04-09T15:23:53Z
       
  • Transmission characteristics and optimal diagnostic samples to detect an
           FMDV infection in vaccinated and non-vaccinated sheep
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): P.L. Eblé , K. Orsel , F. van Hemert-Kluitenberg , A. Dekker
      We wanted to quantify transmission of FMDV Asia-1 in sheep and to evaluate which samples would be optimal for detection of an FMDV infection in sheep. For this, we used 6 groups of 4 non-vaccinated and 6 groups of 4 vaccinated sheep. In each group 2 sheep were inoculated and contact exposed to 2 pen-mates. Viral excretion was detected for a long period (>21 days post-inoculation, dpi). Transmission of FMDV occurred in the non-vaccinated groups (R 0 =1.14) but only in the first week after infection, when virus shedding was highest. In the vaccinated groups no transmission occurred (R v <1, p =0.013). The viral excretion of the vaccinated sheep and the viral load in their pens was significantly lower than that of the non-vaccinated sheep. FMDV could be detected in plasma samples from 12 of 17 infected non-vaccinated sheep, for an average of 2.1 days, but in none of the 10 infected vaccinated sheep. In contrast, FMDV could readily be isolated from mouth swab samples from both non-vaccinated and vaccinated infected sheep starting at 1–3dpi and in 16 of 27 infected sheep up till 21dpi. Serologically, after 3–4 weeks, all but one of the infected sheep were detected using the NS-ELISA. We conclude that vaccination of a sheep population would likely stop an epidemic of FMDV and that the use of mouth swab samples would be a good alternative (instead of using vesicular lesions or blood samples) to detect an FMD infection in a sheep population both early and prolonged after infection.


      PubDate: 2015-04-09T15:23:53Z
       
  • In vitro inhibition of field isolates of feline calicivirus with short
           interfering RNAs (siRNAs)
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Phillip McDonagh , Paul A. Sheehy , Anne Fawcett , Jacqueline M. Norris
      Feline calicivirus (FCV) is a common infection of domestic cats. Most infections are mild and self-limiting; however more severe disease manifestations, such as FCV-associated virulent systemic disease, may be associated with significant morbidity and mortality. There is currently a lack of effective antiviral treatments for these disease manifestations. In this study, a panel of eight siRNAs were designed to target four conserved regions of the FCV genome. siRNAs were screened for in vitro antiviral efficacy against the reference strain FCV F9 by determination of extracellular virus titres and morphological assessment of protection from cytopathic effect. Three of the siRNA (FCV3.7, FCV4.1, and FCV4.2) demonstrated a marked antiviral effect with a greater than 99% reduction in extracellular viral titre. Titration of these effective siRNAs demonstrated a clear concentration–response relationship, with IC50 values of approximately 1nM, and combination treatment with multiple siRNAs demonstrated additive or synergistic effects. To assess the potential usefulness of the compounds in a clinical setting, siRNAs were screened against a panel of six recent Australian FCV isolates from cats with FCV-related disease. The siRNAs shown to be effective against the reference strain FCV F9 were active against the majority of the isolates tested, although some variability was noted. Taken together these data suggest potential therapeutic application of antiviral RNAi for treating FCV-associated disease in cats.


      PubDate: 2015-04-09T15:23:53Z
       
  • Pathogenic characteristics of Marek's disease virus field strains
           prevalent in China and the effectiveness of existing vaccines against them
           
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Yan-ping Zhang , Zhi-jie Li , Ke-yan Bao , Hong-chao Lv , Yu-long Gao , Hong-lei Gao , Xiao-le Qi , Hong-yu Cui , Yong-qiang Wang , Xian-gang Ren , Xiao-mei Wang , Chang-jun Liu
      The virulence of Marek's disease virus (MDV) is continuously evolving, and more virulent MDV pathotypes are emerging, thereby reducing the effectiveness of the existing vaccines. In this study, feather pulps were collected from diseased chickens in commercial chicken flocks in China that presented significant MD visceral tumors in 2011 and were inoculated into a monolayer of duck embryo fibroblasts (DEFs). Three field isolates of MDV were obtained by plaque cloning and identified as MDV via PCR and designated strains LCC, LLY, and LTS. Unvaccinated and CVI988 vaccine-vaccinated specific pathogen-free chickens were challenged at 7 days post vaccination (dpv) with 1000 plaque forming units of each of the respective MDV isolates. These strains induced gross MD lesions in all (100%) of the unvaccinated chickens, and the mortality rates of the unvaccinated chickens were 42.9%, 46.7%, and 23.1% by 60 days post challenge (dpc), respectively. The CVI988 vaccine induced protective indices (PIs) of 85.7, 92.3, and 66.7, respectively. These results showed that the pathogenic characteristics of the Chinese isolates were diverse and that vaccine CVI988 provided different levels of protection against them. These data indicated that the existence of variant MDV strains was a possible reason of immunity failure in China.


      PubDate: 2015-04-09T15:23:53Z
       
  • Experimental susceptibility of European sea bass and Senegalese sole to
           different betanodavirus isolates
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): S. Souto , B. Lopez-Jimena , M.C. Alonso , E. García-Rosado , I. Bandín
      The susceptibility of juvenile European sea bass and Senegalese sole to three VNNV isolates (a reassortant RGNNV/SJNNV, as well as the parental RGNNV and SJNNV genotypes) has been evaluated by challenges using two inoculation ways (bath and intramuscular injection). The results demonstrate that these two fish species are susceptible to all the VNNV isolates tested. In European sea bass, RGNNV caused the highest cumulative mortality, reaching maximum values of viral RNA and titres. Although the SJNNV isolate did not provoke mortality or clinical signs of disease in this fish species, viral production in survivor fish was determined; on the other hand the reassortant isolate did cause mortality and clinical signs of disease, although less evident than those recorded after RGNNV infection. These results suggest that the changes suffered by the SJNNV RNA2 segment of the reassortant isolate, compared to the parental SJNNV, may have involved host-specificity and/or virulence determinants for European sea bass. Regarding Senegalese sole, although the three isolates caused 100% mortality, the reassortant strain provoked the most acute symptoms, and more quickly, especially in the bath challenge. This was also the isolate showing less difference between the number of RNA copies and viral titre, reaching the highest titres of infective viral particles in nervous tissue of infected animals. The RGNNV isolate produced the lowest values of infective viral particles. All these results suggest that the RGNNV and the reassortant isolates are the most suited for infecting European sea bass and Senegalese sole, respectively.


      PubDate: 2015-04-09T15:23:53Z
       
  • Comparison of three commercial one-dose porcine circovirus type 2 (PCV2)
           vaccines in a herd with concurrent circulation of PCV2b and mutant PCV2b
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Jiwoon Jeong , Changhoon Park , Kyuhyung Choi , Chanhee Chae
      Porcine circovirus associated disease (PCVAD) occurred in a farm where pigs had been routinely vaccinated with a commercial PCV2a vaccine. A mutant PCV2b (mPCV2b) was isolated from pigs with PCVAD, perhaps implying a perceived vaccine failure. The objective of this study was to determine and compare the efficacy of 3 one-dose PCV2a vaccines of varying antigen type and dose in the same pig farm with concurrent PCV2b and mPCV2b infection based on clinical (average daily weight gain; ADWG), virological (evidence of viremia), immunological (presence of PCV2-specific neutralizing antibody; NA and interferon-γ secreting cells; IFN-γ-SC), and pathological (lymphoid lesion and PCV2 antigen score within lesion) evaluation. Regardless of which commercial PCV2a vaccine was used, vaccinated animals improved ADWG, and reduced the amount of PCV2b and mPCV2b load in the blood compared to unvaccinated animals. The vaccination of piglets at 3 weeks of age effectively induced higher levels of PCV2b- and mPCV2b-specific NA and IFN-γ-SC compared to unvaccinated animals. A reduction in mPCV2b load in the blood coincided with the appearance of both mPCV2b-specific NA and IFN-γ-SC in the vaccinated animals. The microscopic lymphoid lesions and PCV2-antigen scores within the lymph nodes were significantly lower in vaccinated animals. The perceived vaccine failure could not be explained by incomplete protection of the commercial PCV2a vaccine against mPCV2b. The results of the present study demonstrated that currently available commercial PCV2a vaccines are protective against concurrent PCV2b and mPCV2b infection based on clinical, virological, immunological, and pathological evaluations under field conditions.


      PubDate: 2015-04-09T15:23:53Z
       
  • Evidence of the synergistic interaction of honey bee pathogens Nosema
           ceranae and Deformed wing virus
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Huo-Qing Zheng , Hong-Ri Gong , Shao-Kang Huang , Alex Sohr , Fu-Liang Hu , Yan Ping Chen
      Nosema ceranae and Deformed wing virus (DWV) are two of the most prevalent pathogens currently attacking Western honey bees, Apis mellifera, and often simultaneously infect the same hosts. Here we investigated the effect of N. ceranae and Deformed wing virus (DWV) interactions on infected honey bees under lab conditions and at different nutrition statuses. Our results showed that Nosema could accelerate DWV replication in infected bees in a dose-dependent manner at the early stages of DWV infection. When bees were restricted from pollen nutrition, inoculation with 1×104 and 1×105 spores/bee could cause a significant increase in DWV titer, while inoculation with 1×103 spores/bee did not show any significant effect on the DWV titer. When bees were provided with pollen, only inoculation with 1×105 spores/bee showed significant effect on DWV titer. However, our results also showed that the two pathogens did not act synergistically when the titer of DWV reached a plateau. This study suggests that the synergistic effect of N. ceranae and DWV is dosage- and nutrition- dependent and that the synergistic interactions between the two pathogens could have implications on honey bee colony losses.


      PubDate: 2015-04-09T15:23:53Z
       
  • Experimental co-infections of domestic ducks with a virulent Newcastle
           disease virus and low or highly pathogenic avian influenza viruses
    • Abstract: Publication date: 15 May 2015
      Source:Veterinary Microbiology, Volume 177, Issues 1–2
      Author(s): Mary J. Pantin-Jackwood , Mar Costa-Hurtado , Patti J. Miller , Claudio L. Afonso , Erica Spackman , Darrell R. Kapczynski , Eric Shepherd , Diane Smith , David E. Swayne
      Infections with avian influenza viruses (AIV) of low and high pathogenicity (LP and HP) and Newcastle disease virus (NDV) are commonly reported in domestic ducks in many parts of the world. However, it is not clear if co-infections with these viruses affect the severity of the diseases they produce, the amount of virus shed, and transmission of the viruses. In this study we infected domestic ducks with a virulent NDV virus (vNDV) and either a LPAIV or a HPAIV by giving the viruses individually, simultaneously, or sequentially two days apart. No clinical signs were observed in ducks infected or co-infected with vNDV and LPAIV, but co-infection decreased the number of ducks shedding vNDV and the amount of virus shed (P <0.01) at 4 days post inoculation (dpi). Co-infection did not affect the number of birds shedding LPAIV, but more LPAIV was shed at 2dpi (P <0.0001) from ducks inoculated with only LPAIV compared to ducks co-infected with vNDV. Ducks that received the HPAIV with the vNDV simultaneously survived fewer days (P <0.05) compared to the ducks that received the vNDV two days before the HPAIV. Co-infection also reduced transmission of vNDV to naïve contact ducks housed with the inoculated ducks. In conclusion, domestic ducks can become co-infected with vNDV and LPAIV with no effect on clinical signs but with reduction of virus shedding and transmission. These findings indicate that infection with one virus can interfere with replication of another, modifying the pathogenesis and transmission of the viruses.


      PubDate: 2015-04-09T15:23:53Z
       
  • Genetic diversity of porcine reproductive and respiratory syndrome virus
           in Thailand and Southeast Asia from 2008 to 2013
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Tippawan Jantafong , Pradit Sangtong , Wimontiane Saenglub , Chatthapon Mungkundar , Narin Romlamduan , Chalermpol Lekchareonsuk , Porntippa Lekcharoensuk
      Porcine reproductive and respiratory syndrome virus (PRRSV) affects the swine industry worldwide. Annual surveillances taken from 2008 to 2013 revealed a 13.86% prevalence of PRRSVs in swine populations in Thailand. The selected positive samples were genetically characterized based on global systems and phylogenetic trees that were constructed using 967 ORF5 samples from this study, the collective sequences from Thailand and Southeast Asia and reference sequences. The results showed that both types I and II have been circulating in Thai swine and that genotype II was more prevalent than genotype I. Only type II was found in other countries in Southeast Asia. Type I PRRSVs from Thailand are clustered in subtype 1, clades A, D and H. Type II PRRSVs are topologically classified in lineage 1 and sublineages 5.1, 5.2 and 8.7, of which sublineage 8.7 was predominant, especially after 2010. PRRSVs in sublineage 8.7 are divided into two groups: classical NA and HP-PRRSV. An analysis of all HP-PRRSVs in Southeast Asia revealed four separate clades – A (SX2009-like), B (09HEN1-like), JXA1-like and GXFCH08-like – reflecting four different introductions of these viruses into Thailand, Lao PDR, Cambodia and Vietnam. HP-PRRSV first appeared in Thailand and Cambodia in 2008, 2 years before the first epidemic outbreaks. Recently, the genetics of PRRSVs in Southeast Asia have become more diverse. Thus, PRRSV genetics must be continually characterized and phylogenetically analyzed using global systematic classifications to provide annual genetic information for PRRS control and vaccine selection.


      PubDate: 2015-04-04T14:46:10Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4




      PubDate: 2015-04-04T14:46:10Z
       
  • Virological and serological investigation of Equid herpesvirus 1 infection
           in New Zealand
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): M. Dunowska , G. Gopakumar , M.R. Perrott , A.T. Kendall , S. Waropastrakul , C.A. Hartley , H.B. Carslake
      Infection with equid herpesvirus 1 (EHV-1) may be asymptomatic, or may result in respiratory disease, abortion, neonatal death, or neurological disease. The aim of this study was to estimate the prevalence of EHV-1 infection, including differentiation between genotypes with aspartic acid (D) and asparagine (N) at position 752 of the DNA polymerase sequence, within a selected population of New Zealand horses. The second aim was to determine the predictive value of serology for detection of latently infected horses. Retropharyngeal lymph nodes (RLN) and trigeminal ganglia (TG) were dissected from 52 horses at slaughter and tested for the presence of EHV-1 DNA using magnetic bead, sequence-capture enrichment followed by nested PCR. Sera were tested for EHV-1 antibody using type-specific glycoprotein G ELISA. Overall, 17/52 horses tested positive for EHV-1 DNA. All but one positive PCR results were obtained from RLN samples. Fifteen of the EHV-1 positive horses harboured EHV-1 with N752 genotype, one of which was additionally infected with the D752 genotypes of the virus. Our data comprise the first detection of EHV-1 with D752 genotype in New Zealand and suggest that the “neurovirulent” variant of EHV-1 had been present in New Zealand for at least two years before the first reported outbreak of EHM. All sampled horses tested positive for EHV-4 antibody, and 11/52 tested positive for EHV-1 antibody. The strength of agreement between results of EHV-1 PCR and EHV-1 serology was “fair” (Kappa 0.259, 95% CI: −0.022–0.539), which was likely a reflection of low levels of both EHV-1 antibody in sera and EHV-1 DNA in tissues tested.


      PubDate: 2015-04-04T14:46:10Z
       
  • Septicaemia and meningitis caused by infection of New Zealand sea lion
           pups with a hypermucoviscous strain of Klebsiella pneumoniae
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): W.D. Roe , L. Rogers , K. Pinpimai , K. Dittmer , J. Marshall , B.L. Chilvers
      This study describes a syndrome of neonatal septicemia and meningitis in New Zealand sea lions, caused by a strain of Klebsiella pneumoniae that is phenotypically similar to strains causing environmentally-acquired septicemia and neuro-invasive disease in humans. Between late 2006 and early 2010, 123 pups from the Enderby Island breeding colony died of K. pneumoniae infection, with lesions including fibrinous to fibrinosuppurative meningitis, subdural hemorrhage, septic arthritis, herniation and hemorrhage of the cerebellar vermis, lymphadenitis and cellulitis. This infection was responsible for 58% of observed pup mortality over this time period, with most deaths occurring in the latter part of the breeding season (mid February onwards). The results of this study suggest that the pattern of this disease has changed since it was first described in 2002, when most deaths occurred early in the season (early to mid-January), and that it is an important and consistent cause of pup mortality in this population. In addition, a similar disease syndrome and bacterial strain was diagnosed in a single pup in a fragile recolonizing New Zealand sea lion population on mainland New Zealand, and the potential effect on this population is unknown but could have a negative impact on recolonisation at this site.


      PubDate: 2015-04-04T14:46:10Z
       
  • Pseudomonas fluorescens: Iron-responsive proteins and their involvement in
           host infection
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Yuan-yuan Sun , Li Sun
      For pathogenic bacteria, the ability to acquire iron is vital to survival in the host. In consequence, many genes involved in iron acquisition are associated with bacterial virulence. Pseudomonas fluorescens is a bacterial pathogen to a variety of farmed fish. However, the global regulatory function of iron in pathogenic P. fluorescens is essentially unknown. In this study, in order to identify proteins affected by iron condition at the expression level, we performed proteomic analysis to compare the global protein profiles of P. fluorescens strain TSS, a fish pathogen, cultured under iron-replete and iron-deplete conditions. Twenty-two differentially expressed proteins were identified, most of which were confirmed to be regulated by iron at the mRNA level. To investigate their potential involvement in virulence, the genes encoding four of the 22 proteins, i.e. HemO (heme oxygenase), PspB (serine protease), Sod (superoxide dismutase), and TfeR (TonB-dependent outermembrane ferric enterobactin receptor), were knocked out, and the pathogenicity of the mutants was examined in a model of turbot (Scophthalmus maximus). The results showed that compared to the wild type, the hemO, pspB, and tfeR knockouts were significantly impaired in the ability to survive in host serum, to invade host tissues, and to cause host mortality. Immunization of turbot with recombinant TfeR (rTfeR) and PspB induced production of specific serum antibodies and significant protections against lethal TSS challenge. Further analysis showed that rTfeR antibodies recognized and bound to TSS, and that treatment of TSS with rTfeR antibodies significantly impaired the infectivity of TSS to fish cells. Taken together, these results indicate for the first time that in pathogenic P. fluorescens, iron affects the expression of a large number of proteins including those that are involved in host infection.


      PubDate: 2015-04-04T14:46:10Z
       
  • Efficacy of liposomal gentamicin against Rhodococcus equi in a mouse
           infection model and colocalization with R. equi in equine alveolar
           macrophages
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Alexandra J. Burton , Steeve Giguère , Londa J. Berghaus , Mary K. Hondalus , Robert D. Arnold
      Rhodococcus equi, a facultative intracellular pathogen and an important cause of pneumonia in foals, is highly susceptible to killing by gentamicin in vitro. However, gentamicin is not effective in vivo, due to its poor cellular penetration. Encapsulation of drugs in liposomes enhances cellular uptake. The objectives of this study were to compare liposomal gentamicin and free gentamicin with respect to their uptake by equine macrophages and intracellular colocalization with R. equi and to compare the efficacies of liposomal gentamicin, free gentamicin and clarithromycin with rifampin for the reduction of R. equi CFU in a mouse model of infection. After ex vivo exposure, a significantly higher mean (±SD) percentage of equine alveolar macrophages contained liposomal gentamicin (91.9±7.6%) as opposed to free gentamicin (16.8±12.5%). Intracellular colocalization of drug and R. equi, as assessed by confocal microscopy, occurred in a significantly higher proportion of cells exposed to liposomal gentamicin (81.2±17.8%) compared to those exposed to free gentamicin (10.4±8.7%). The number of R. equi CFU in the spleen was significantly lower in mice treated with liposomal gentamicin compared to that of mice treated with free gentamicin or to untreated control mice. Treatment with liposomal gentamicin also resulted in a significantly greater reduction in the number of R. equi CFU in the liver compared to treatment with clarithromycin in combination with rifampin. These results support further investigation of liposomal gentamicin as a new treatment for infections caused by R. equi.


      PubDate: 2015-04-04T14:46:10Z
       
  • Reappearance of Salmonella serovar Choleraesuis var. Kunzendorf in Danish
           pig herds
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Karl Pedersen , Gitte Sørensen , Charlotta Löfström , Pimlapas Leekitcharoenphon , Bent Nielsen , Anne Wingstrand , Frank M. Aarestrup , René S. Hendriksen , Dorte Lau Baggesen
      Salmonella enterica serovar Choleraesuis is a porcine adapted serovar which may cause serious outbreaks in pigs. Here we describe outbreaks of salmonellosis due to S. Choleraesuis in four Danish pig farms in 2012–2013 by clinic, serology, and microbiology and compare the isolates to those of a previous outbreak in 1999–2000. The infection was in some herds associated with high mortality and a moderate to high sero-prevalence was found. In 2012–2013 the disease contributed to increased mortality but occurred concomitant with other disease problems in the herds, which likely delayed the diagnosis by up to several months. Nine isolates from the four farms in 2012–2013 and 14 isolates obtained from the outbreak in Denmark in 1999–2000 were subjected to typing using pulsed-field gel electrophoresis (PFGE). Seven isolates were selected for whole genome sequencing (WGS). The PFGE results of 23 isolates displayed five different profiles. The isolates from 2012 to 2013 revealed two distinct profiles, both different from the isolates recovered in 1999–2000. Two of the 2012–2013 farms shared PFGE profiles and had also transported pigs between them. The profile found in the two other 2012–2013 farms was indistinguishable but no epidemiological connection between these farms was found. Analysis of the number of single nucleotide polymorphisms (SNPs) from the WGS data indicated that the isolates from the farms in 2012–2013 were more closely related to each other than to isolates from the outbreak in 1999. It was therefore concluded that the infection was a new introduction and not a persistent infection since the outbreak in 1999. It may further be suggested that there were two or three independent rather than a single introduction. The re-introduction of S. Choleraesuis in Denmark emphasizes the importance of strict hygiene measures in the herds. Further investigations using WGS are now in progress on a larger collection of isolates to study clonality at European level and trace the origin of the infections.


      PubDate: 2015-04-04T14:46:10Z
       
  • Detection in and circulation of Bluetongue virus among domestic ruminants
           in Madagascar
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Soa Fy Andriamandimby , Cyril Viarouge , Jean-Pierre Ravalohery , Jean-Marc Reynes , Corinne Sailleau , Michael Luciano Tantely , Nohal Elissa , Eric Cardinale , Amadou Alpha Sall , Stephan Zientara , Jean-Michel Heraud
      So far, no published data was available concerning the circulation of Bluetongue virus (BTV) in Madagascar. During a survey on Rift Valley Fever, we were able to detect a virus belonging to BTV. Therefore, we conducted a study aiming at characterizing molecularly the BTV isolated and assess the importance of circulation of BTV in Madagascar. A total of 4393 sera from ruminants selected randomly by stratification and sampled in 30 districts of Madagascar were tested for BTV. Moreover, 175 cattle were followed during 11 months. Phylogenetic analyses were performed from virus isolated from unfed pools of mosquitoes. Overall, the estimated mean seroprevalence of infection at the national level was 95.9% (95% CI: [95.2–96.5]) in cattle and 83.7% (95% CI: [81.4–85.9]) in small ruminants. Estimation of incidence rate was 54 per 100 cattle-years assuming that the incidence rate is constant all year along. Phylogenetic analyses revealed that BTV detected belong to serotype 2. In conclusion, our results showed that BTV is endemic in Madagascar and highly prevalent among cattle. In our study we did not work on the vector involved in transmission of BTV in cattle. Thus, research should be conducted to better describe epidemiology of BTV in Madagascar including vectors and assess economic impact of the disease associated to BTV infections.


      PubDate: 2015-04-04T14:46:10Z
       
  • Extent of Mycobacterium bovis transmission among animals of dairy and beef
           cattle and deer farms in South Korea determined by variable-number tandem
           repeats typing
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Sungmo Je , Bok Kyung Ku , Bo-Young Jeon , Jae-Myoung Kim , Suk-Chan Jung , Sang-Nae Cho
      Identifying sources of Mycobacterium bovis transmission would be essential for establishing effective control programs of bovine tuberculosis (TB), a major zoonosis threatening human health worldwide. As an effort to determine the extent of M. bovis transmission among dairy and beef cattle and deer populations, a mycobacterial interspersed repetitive units (MIRU)-variable-number tandem repeats (VNTR) typing method was employed for analysis of 131 M. bovis isolates from 59 Holstein dairy cattle, 39 Korean beef cattle, and 33 deer. Of 31 MIRU-VNTR markers, 15 showed allelic diversity. The most discriminatory locus for M. bovis isolates was VNTR 3336 (h =0.59) followed by QUB 26, MIRU 31, VNTR 2401, and VNTR 3171 which showed high discriminatory power (h =0.43). The combined VNTR loci had an allelic diversity of 0.83. On the basis of the VNTR profiles of 30 VNTR loci, 24 genotypes were identified, and two genotypes were highly prevalent among all M. bovis isolates (33.6% and 19.1%, respectively), thus indicating that more than 50% of the isolates shared common molecular characteristics. Six additional genotypes were common in 2 of the 3 animal species, suggesting a wide interspecies transmission of M. bovis. This study thus demonstrates that MIRU-VNTR typing is useful in differentiation of M. bovis isolates and that M. bovis transmission occurs frequently among farmed animal species, highlighting the importance of bovine TB control programs in different animal species which are often raised in the same villages.


      PubDate: 2015-04-04T14:46:10Z
       
  • Effect of deoxynivalenol (DON) mycotoxin on in vivo and in vitro porcine
           circovirus type 2 infections
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Christian Savard , Chantale Provost , Fernando Alvarez , Vicente Pinilla , Nedzad Music , Mario Jacques , Carl A. Gagnon , Younes Chorfi
      Deoxynivalenol (DON) is a mycotoxin produced by Fusarium spp and is a common contaminant of grains in North America. Among farm animals, swine are the most susceptible to DON because it markedly reduces feed intake and decreases weight gain. Porcine circovirus type 2 (PCV2) is the main causative agent of several syndromes in weaning piglets collectively known as porcine circovirus-associated disease (PCVAD). The objectives of this study were to investigate the impact of DON on PCV2 replication in NPTr permissive cell line, and to determine eventual potentiating effects of DON on PCV2 infection in pigs. Noninfected and infected cells with PCV2 were treated with increasing concentrations of DON (0, 70, 140, 280, 560, 1200ng/mL) and cell survival and virus titer were evaluated 72h postinfection. Thirty commercial piglets were randomly divided into 3 experimental groups of 10 animals based on DON content of served diets (0, 2.5 and 3.5mg/kg DON). All groups were further divided into subgroups of 6 pigs and were inoculated with PCV2b virus. The remaining pigs (control) were sham-inoculated with PBS. In vitro results showed that low concentrations of DON could potentially increase PCV2 replication depending on virus genotype. In vivo results showed that even though viremia and lung viral load tend to be higher in animal ingesting DON contaminated diet at 2.5mg/kg, DON had no significant effect on clinical manifestation of PCVAD in PCV2b infected animals. DON has neither in vitro nor in vivo clear potentiating effects in the development of porcine circovirus infection despite slight increases in viral replication.


      PubDate: 2015-04-04T14:46:10Z
       
  • The anti-canine distemper virus activities of ex vivo-expanded canine
           natural killer cells
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Ji-Yun Park , Dong-Jun Shin , Soo-Hyeon Lee , Je-Jung Lee , Guk-Hyun Suh , Duck Cho , Sang-Ki Kim
      Natural killer (NK) cells play critical roles in induction of antiviral effects against various viruses of humans and animals. However, few data on NK cell activities during canine distemper virus (CDV) infections are available. Recently, we established a culture system allowing activation and expansion of canine non-B, non-T, large granular NK lymphocytes from PBMCs of normal dogs. In the present study, we explored the ability of such expanded NK cells to inhibit CDV infection in vitro. Cultured CD3−CD5−CD21− NK cells produced large amounts of IFN-γ, exhibited highly upregulated expression of mRNAs encoding NK-cell-associated receptors, and demonstrated strong natural killing activity against canine tumor cells. Although the expanded NK cells were dose-dependently cytotoxic to both normal and CDV-infected Vero cells, CDV infection rendered Vero cells more susceptible to NK cells. Pretreatment with anti-CDV serum from hyperimmunized dogs enhanced the antibody-dependent cellular cytotoxicity (ADCC) of NK cells against CDV-infected Vero cells. The culture supernatants of NK cells, added before or after infection, dose-dependently inhibited both CDV replication and development of CDV-induced cytopathic effects (CPEs) in Vero cells. Anti-IFN-γ antibody neutralized the inhibitory effects of NK cell culture supernatants on CDV replication and CPE induction in Vero cells. Such results emphasize the potential significance of NK cells in controlling CDV infection, and indicate that NK cells may play roles both during CDV infection and in combating such infections, under certain conditions.


      PubDate: 2015-04-04T14:46:10Z
       
  • H2 genotypes of G4P[6], G5P[7], and G9[23] porcine rotaviruses show
           super-short RNA electropherotypes
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Makoto Nagai , Saya Shimada , Yoshiki Fujii , Hiromitsu Moriyama , Mami Oba , Yukie Katayama , Shinobu Tsuchiaka , Sachiko Okazaki , Tsutomu Omatsu , Tetsuya Furuya , Satoshi Koyama , Junsuke Shirai , Kazuhiko Katayama , Tetsuya Mizutani
      During group A rotavirus (RVA) surveillance of pig farms in Japan, we detected three RVA strains (G4P[6], G5P[7], and G9P[23] genotypes), which showed super-short RNA patterns by polyacrylamide gel electrophoresis, in samples from a healthy eight-day-old pig and two pigs of seven and eight days old with diarrhea from three farms. Reverse transcription PCR and sequencing revealed that the full-length NSP5 gene of these strains contained 952 or 945 nucleotides, which is consistent with their super-short electropherotypes. Due to a lack of whole genome data on Japanese porcine RVAs, we performed whole genomic analyses of the three strains. The genomic segments of these RVA strains showed typical porcine RVA constellations, except for H2 NSP5 genotype, (G4,5,9-P[6,7,23]-I5-R1-C1-M1-A8-N1-T1-E1-H2 representing VP7-VP4-VP6-VP1-VP2-VP3-NSP1-NSP2-NSP3-NSP4-NSP5 genes). In phylogenetic analyses, these porcine RVA strains clustered with porcine and porcine-like human RVA strains and showed a typical porcine RVA backbone, except for the NSP5 gene; however, intra-genotype reassortment events among porcine and porcine-like human RVA strains were observed. The NSP5 gene segments of these strains were clustered within the H2b genotype with super-short human RVA strains. The H2 genotype has to date only been identified in human and lapine RVA strains. Thus, to our knowledge, this report presents the first case of H2 NSP5 genotype showing a super-short RNA pattern in porcine RVA. These data suggest the possibility of interspecies transmission between pigs and humans and imply that super-short porcine RVA strains possessing H2 genotype are circulating among both asymptomatic and diarrheic porcine populations in Japan.


      PubDate: 2015-04-04T14:46:10Z
       
  • Understanding and managing bTB risk: Perspectives from Ireland
    • Abstract: Publication date: 17 April 2015
      Source:Veterinary Microbiology, Volume 176, Issues 3–4
      Author(s): Simon J. More , Margaret Good
      There is substantial variation in herd risk for bovine tuberculosis (bTB) in Ireland, with most herds playing little to no role in the ongoing endemic. In infected areas, bTB persistence (affecting one or a group of herds) is a key feature of the infection. In this paper, we present our current understanding and management of bTB risk in Ireland, based on a detailed review of research and policy. There is close interaction between science and policy in Ireland, seeking both to understand and effectively manage bTB risk. Detailed research on bTB persistence is presented, including current understanding of the relative importance of different infection sources, which can include residual infection in cattle and/or re-infection, either from local sources or following cattle introduction. In recent years, there have been three primary drivers for policy change, including scientific advances, ongoing improvements to programme supports, and ongoing programme review. In this review, three key future programme challenges are identified. Although good progress is being made, eradication has not yet been achieved. Firstly, a key question concerns the additional effort that will be required, to move towards final eradication. Secondly, a percentage of non-infected animals are falsely positive to current testing methods. This is an ongoing challenge, given the imperfect specificity of test methods but will become more so, as the positive predictive value falls with reducing bTB prevalence. Finally, there is a need to re-engage with the farming community, so that they play a much greater role in programme ownership.


      PubDate: 2015-03-11T18:28:58Z
       
 
 
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